Electric barrier to deter goby might be solution to reopening of Menasha lock to boaters

The Wisconsin Department of Natural Resources is asking for the public's help in monitoring Lake Winnebago for round gobies.
Duke Behnke/USA TODAY NETWORK-Wisconsin

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Algae covers the water in the Menasha lock, which has been closed since 2015 to stop the spread of the round goby, an aquatic invasive species.(Photo11: Danny Damiani/USA TODAY NETWORK-Wisconsin)Buy Photo

MENASHA - The creation of a low-voltage electric field in the water immediately downstream of the Menasha lock continues to be a focus of research as a way to deter invasive fishes like the round goby from swimming upstream to Lake Winnebago and its prized fishery.

Jeremy Cords, executive director of the Fox River Navigational System Authority (FRNSA), said an electric barrier could be the key to reopening the Menasha lock to boaters traveling between Lake Winnebago and Little Lake Butte des Morts.

The lock has been closed since 2015 by order of the Wisconsin Department of Natural Resources to block the spread of the round goby.

Electric barriers have proven effective in other parts of the country and world, Cords said. The system discharges a pulsating direct current in the water that's designed to repel fish, not kill them. The current would get progressively stronger the closer a fish swam to the lock.

Jeremy Cords, executive director of the Fox River Navigational System Authority(Photo11: Submitted)

Cords said the electric barrier doesn't pose a danger to people and wouldn't be felt by boaters unless they stuck their hand in the water. He said the current would be "way less" than that of an electric fence.

"The company that has the cornerstone on this technology says people have swam through these electric barriers without any injury," Cords said. "They said they can feel it — it's like a tingle — but it's not anything that impairs their ability to move or leaves them with any type of injury."

Other options under review

While much of FRNSA's focus has been on the electric barrier in the past nine months, four other options remain under consideration for the resumption of boat traffic between Lake Winnebago and the lower Fox River.

Keep the Menasha lock sealed and build a crane to lift boats over the lock.

Keep the lock sealed and build a crane to lift boats over the levee by the lock.

Keep the lock sealed and build an adjacent concrete road so a marine forklift can scoop boats from the water and carry them past the lock.

Reopen the lock after infusing carbon dioxide into the water to create an oxygen-depleted zone that would prevent fish from swimming upstream.

The options to lift boats out of the water would include a boat cleaning station using hot water, a chemical solution or both.

"Nothing is off the table right now," Cords said. "We're trying to consider everything."

Three options to lift boats past the closed Menasha lock are under consideration. Two other options would reopen the lock. One would create an electric barrier for fish, and the other would create an oxygen-depleted barrier for fish.(Photo11: Courtesy of FRNSA)

FRNSA has spent more than $70,000 researching the options at the Menasha lock. That's in addition to the more than $200,000 it previously spent researching options at the closed Rapide Croche lock near Wrightstown.

Finding a solution at the Menasha lock is the priority, Cords said. FRNSA has been working closely with the DNR throughout the process.

"We're working hard to open up the lock, but we also are working hard to protect the fishery in Lake Winnebago," he said. "They are real concerns, and we want to be 100 percent accurate before we do this."

Drawbacks to consider

All of the options pose challenges, and they can be costly when calculating construction and operational expenses.

The low bid for the construction of a boat transfer station at the Rapide Croche lock totaled $8.2 million last year. It was deemed cost-prohibitive and rejected.

Constructing a boat lift at the Menasha lock, complete with steel beams, rigs and trolleys, could alter the historic character of the lock. The effect must be evaluated because the Fox River locks are listed on the National Register of Historic Places.

The historic preservation issue is avoided by building a boat lift over the levee, but that location would require extensive dredging in Little Lake Butte des Morts. It also would interfere with traffic on the Fox Cities Trestle/Friendship Trail.

Constructing a road for the forklift could disturb the land and possible artifacts.

Lifts also typically provide a slower passage in comparison to the lock.

"You wouldn't be able to achieve an equivalent amount of throughput," said boater Bryan Mick, a member of the Appleton Yacht Club board of directors. "You just wouldn't have the capacity of what the lock has."

Although electric barriers are in use in Michigan, Illinois, Iowa and Minnesota, Cords said they are unfamiliar to Wisconsin and would require educating the public.

"We'd be the first one," he said. "People think, 'OK, electric barrier, I can't touch the water or I might get electrified,' which is not true."

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The Fox River Navigational System Authority is evaluating the use of an electric barrier downstream of the Menasha lock.(Photo11: Wm.Glasheen/USA TODAY NETWORK-Wisconsin)

Mick said an electric barrier holds the most promise for being effective against the goby and efficient for boaters.

"It would achieve the same amount of throughput on the lock while protecting the waterway, which is significant," Mick said. "We do have to protect it."

A carbon dioxide barrier also shows promise, but the technology and its effects on the environment haven't been as thoroughly tested as an electric barrier.

Whatever option is pursued, implementation will take at least a year.

"If the decision was made today to go ahead with any one of those options," Cords said, "the earliest the lock would be open would be the fall of next year."

Invasive species threat

The round goby is a bottom-feeding fish that preys on sport fish eggs. The goby generally is limited to the Great Lakes but somehow found its way to the lower Fox River. It was discovered below the Neenah dam in 2015.

The DNR since has determined that the species has a reproducing population in Little Lake Butte des Morts.

To date, the closure of the Menasha lock appears to have had the desired effect. The DNR has no confirmed report of a round goby in Lake Winnebago.

"That's a very good thing," said Kendall Kamke, the DNR's Oshkosh fisheries team supervisor.

Kamke said boaters need to take precautions to prevent the spread of the goby and other invasive species.

The first items on an angler's checklist, he said, no longer should be fishing poles, tackle boxes and bait, but rather whether the boat has been disinfected between travels from one body of water to the next.

The round goby ranges in size from 3 to 6 inches and has a mottled gray appearance. It can be identified by a single, scallop-shaped pelvic fin on the belly, a black spot on the front dorsal fin, frog-like raised eyes and thick lips. No native Great Lakes fish has a single pelvic fin.

Anglers who catch a goby upstream of the Neenah and Menasha dams should:

Place it in a plastic bag on ice.

Record specific information about where and when it was caught.

Bring it to a local DNR office.

Alternatively, anglers can take a picture of the goby and report it to the DNR using an online form.

Outside of identification purposes, the round goby is illegal to possess, transport or use as bait.

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Boaters, canoeists and kayakers have been longing for the reopening of the Menasha lock.(Photo11: File/USA TODAY NETWORK-Wisconsin)